Comment 3 for bug 351122

F-spot works fine with this. gthumb should do what f-spot does and communicate using the gphoto:/// gvfs URI as opposed to trying to directly talk to the camera like it does now. This is how f-spot does it.

And how are you actually recreating this problem? The gthumb-import desktop file which Nautilus uses to launch gthumb when a camera is connected, contains a fix that has been in since Intrepid to actually unmount the gvfs mount before opening gthumb. This is what Nautilus executes when launching gthumb in response to you connecting your camera:

sh -c 'gvfs-mount -u "%U"; exec gthumb --import-photos'

This was implemented as the "fix" for bug 287689 in Intrepid, so if this is not working then this is most certainly a gthumb bug.